With Jennifer Lawrence, Russell Crowe, and Naomi Watts on the guest list, Vanity Fair and Armani’s Cannes Film Festival party, hosted by Graydon Carter and Giorgio Armani at the luxe Hotel du Cap tonight, was bound to be one of the most buzzed-about parties during this party-happy festival. But the surprise arrival of Justin Bieber, clad in his trademark low-slung pants and gleaming white moon shoes, made even the film royalty in attendance star-struck.

Bieber, a last-minute addition brought in by Vanity Fair’s Elizabeth Saltzman and shepherded around the pre-party dinner by none other than IAC chairman Barry Diller, was in high photo-op demand as he navigated the party, posing with Russell Crowe and seemingly exchanging “let’s hang out, bro” phone numbers with Adrian Grenier. But the most excited to meet Bieber was Jennifer Lawrence, who was overheard loudly saying “I want to meet Bieber!!” immediately upon arrival.

Ever interested in fostering interesting friendships, your trusty V.F. staff were able to arrange the historic meeting. Lawrence declined a photograph, saying she wanted Justin and herself to meet as real people. But we can confirm that they did indeed exchange pleasantries, and that the party was made all the better for it.

We also spotted Lawrence shrieking with delight as Oscar-winning director Alfonso Cuarón popped over to say hello. And he seemed excited to meet her.

Elsewhere, Robert Pattinson, putting Twilight behind him with two dark films in the festival, was perhaps comparing teen-avoidance strategy with fellow Y.A. franchise hero Liam Hemsworth, who, with costars Lawrence and Sam Claflin, arrived following their own Hunger Games party.